Functions and Features&colon; 1 Full metal jacket&comma; elegance&comma; aesthetic2 Hands free two-way talkback full automaticity3 Micro computer control circuit with squelch function&comma; can thoroughly solve echo and squeal problems&period; 4 Adopt high-powered mic&comma; elegant appearance&comma; voice is lifelike&comma; clear&semi; Th volume of master station and substation can be adjusted separately by oneself5 Easy installation&comma; there is only one wire for connecting master station and substation&period; 6 Have output for recording&comma; can connect record equipment external&period; 7 Widely use at any window internal&sol;external intercom&comma; the place which difficult to talk&period;